Need to Reference the US Constitution Fast? How’s 6 Seconds Sound?

CONSTI2GO-Thibault-Brevet-2

Well, unless you know exactly what you’re referencing it’s going to take you a lot longer, but this clever serial receipt printer hack will let you print the whole darn thing in just 6 seconds!

Commissioned by [Jeff Goldenson] for his LABRARY.bike (quite literally a pop-up library on a bike), it was actually shown off at SXSW Interactive — did anyone see it in person? The artist-hacker who created it is [Thibault Brevet], the guy who brought us the DRM chair that only works 8 times before it falls to pieces.

Anyway, this cool and rather suspicious looking tube with a serial cord hanging out contains an Arduino, a max232 chip and a small Li-Po battery. The Arduino communicates with the printer through the max232 chip by converting the TTL signal to RS-232. It has a single button on top, which when it is connected to the printer will send out the US Constitution over the serial interface via ESC/p language.

Did we mention how fast it is?

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Meet Lynx, a (costly) Offline Password Keeper

Maybe because he didn’t want to wait for the Mooltipass to be produced, [davidhend] built himself his own offline password keeper, named Lynx.

It is based around an Arduino Pro 328, a 2.8″ TFT touch screen, an RFID card reader, an FTDI basic breakout and finally a li-ion battery. Lynx is therefore self-powered and uses an RFID card to later read the XOR-encrypted passwords located in a SD card. A USB serial connection is used to send the passwords to the computer, which also charges the battery. The current BoM cost is around $220 but we’re quite sure it can be made for much cheaper when not using pre-made boards. Looking at the official GitHub repository tells us that the XOR key is stored inside the microcontroller and that Lynx checks the RFID card code to allow encryption/decryption.

On a side note, we recently published a FAQ on the official Mooltipass GitHub. You’re welcome to let us know what questions we may have forgotten.

Mug Music Is Good to the Last Drop

[Bonnie] is majoring in CS at Princeton and minoring in Awesome. She is taking an electronic music class and had to produce a digital instrument for her midterm project. She and her friend [Harvest] came up with Mug Music, which turns a ceramic mug of water into an instrument.

The circuit is very easy to replicate with an Arduino, a coil, and a few resistors and capacitors. [Bonnie] wanted to experiment with Disney Research Lab’s Touché method of touch detection, and Mug Music is based on this Touché for Arduino Instructable. The inputs are turned into MIDI notes with ChucK, a real-time sound synthesis language developed at Princeton.

As you may have guessed and will see in the demonstration video after the jump, you aren’t limited to touching the water. The entire mug will produce sounds as well. [Bonnie] says you can trigger a thunderclap if you touch the water and a grounded surface simultaneously.

This would be a great project to explore with kids, especially as a music therapy vehicle for kids on the autism spectrum. It isn’t as physical as these portable musical stairs, but it may draw less attention from lawyers.

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GEVCU – an Open Generalized Electric Vehicle Control Unit

At Hackaday we’re very happy to see the increasing number of open hardware devices that appear everyday on the internet, and we’re also quite thrilled about open-source electric cars. Pictured above is the GEVCU, an open source electric vehicle control unit (or ECU). It is in charge of processing different inputs (throttle position, brake pressure, vehicle sensors) then send the appropriate control commands to electric motor controllers (aka inverters) via CAN bus messages or digital / PWM signals.

The project started back in December 2012 and was originally based on an Arduino Due. Since then, the GEVCU went through several revisions and ultimately a complete custom board was produced, while still keeping the Cortex M3 ATSAM3X8E from the Due. As you may have guessed, the board also includes a Wifi transceiver so users may adjust the ECU parameters via a web based platform. All resources may be downloaded from the official GitHub.

Listening to Electromagnetic Interference with a RTLSDR Dongle

Being curious by nature, [Marios] decided to see what kind of radio-frequency emissions may be generated by an Arduino connected to a simple breadboard wire, and more importantly try to pick them up using a RTLSDR dongle. Electromagnetic interferences are disturbances that affect electrical circuits due to either electromagnetic induction or electromagnetic radiation. Before going into the market, all electrical devices are thoroughly checked for unwanted electromagnetic emissions so they usually aren’t obvious suspects when such problems arise.

Using the Arduino embedded PWM controller in fast PWM mode and by manipulating the duty cycle, he actually managed to create a primitive form of amplitude modulation and was able to transfer a very simple audible signal at several frequencies up to 1.75GHz. Embedded after the break here is video of the system at work.

As a side note, did you know that during the solar storm of 1859 the EMI were so strong that the telegraph operators received several shocks? Pipelines maintenance systems also have to be aware of such events, that can lead sensors to provide inaccurate results.

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Handheld Tetris is Retro and We Love It

handheld tetris

[Eduardo Zola] has been playing around with Arduinos, and ever since he started, he wanted to try making a game. Having fond memories of playing Tetris back on Windows 3.1, he decided to try giving a handheld version of it a shot.

He started with two 8×8 Neopixel Matrices due to their simplicity — not to mention the massive library of code available! To make it truly portable, he’s also included a 3.7v 4400mAh lithium ion battery which will keep him gaming for hours. He found a 5-way navigation switch on eBay which makes up the joystick. A small LED bar display tells you what level you’re on, and he’s even included a smaller speaker for music, and a vibrating motor for successfully completed lines in the game!

He borrowed the Tetris algorithm (and added some improvements) from the source code by [Valentin Ivanov], who completed a similar project last fall. Stick around to see a demonstration video of it in action.

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Old Inkjet Turned Into An SVG Plotter

plotter

What do you do when you have an old printer, a portable CD player, and a handful of other electronics sitting around? Turn it into a plotter, of course.

The frame of the plotter was taken from a ye olde Epson printer, reusing the two stepper motors to move the paper along its length and width. The pen is attached to the laser head of a junked portable CD player. With this, it’s just three stepper motors that allow the Arduino control system to move the pen across the paper and put a few markings down.

The motors on the printer are, in the spirit of reuse, still connected to the printer’s driver board, with a few leads going directly from the Arduino to the parallel port interface. The motor in the CD player is another ordeal, with a single H-bridge controlling the lifting of the pen.

On the software side of things, a Processing sketch reads an SVG file and generates a list of coordinates along a path. The precision of the coordinates is set as a variable, but from the video of the plotter below, this plotter has at least as much resolution as the tip of the pen.

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